Oral, Fecal and Intratumoral Microbiome Atlas in Colombian Patients With Advanced Solid Tumors Receiving First-Line Immunotherapy (ATLAS)

July 3, 2026 updated by: Centro de Tratamiento e Investigación sobre Cáncer, Luis Carlos Sarmiento Angulo

Atlas of the Oral, Fecal and Intratumoral Microbiome of Colombian Patients With Advanced Solid Tumors Candidates for First-Line Immunotherapy - Initial Phase of a Project With Latin American Projection

This is a prospective observational cohort study conducted at Fundación CTIC in Bogotá, Colombia. It characterizes the oral, fecal and intratumoral microbiome of Colombian adults with advanced solid tumors (gastric, colorectal, breast, cervical and head-and-neck cancer) who receive first-line immunotherapy as standard of care, and compares them with healthy volunteers. Using multi-omics (HiFi metagenomics, 16S, tumor RNA-Seq and untargeted metabolomics), the study aims to identify microbial signatures associated with treatment response and survival, building the initial Colombian cohort of a Cancer Microbiome Atlas with Latin American projection.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Single-center, prospective, observational cohort study. 120 patients with advanced (stage III unresectable or IV) solid tumors candidates for first-line immunotherapy and 30 healthy controls are enrolled (total N=150). Patients provide saliva, stool and tongue-scraping samples plus archival FFPE tumor tissue at baseline (V0) and at 6 (V1) and 12 (V2) months; controls provide saliva and stool at V0 only. Microbiomes are profiled by PacBio HiFi shotgun metagenomics and full-length 16S; tumor transcriptome by RNA-Seq; and saliva/stool metabolome by GC-MS in a subcohort (n=60). Tumor response is assessed by RECIST 1.1. Microbial, transcriptomic and metabolomic features are integrated with clinical outcomes (objective response, PFS, OS) using multivariable and machine-learning models.

Study Type

Observational

Enrollment (Estimated)

150

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

  • Name: Andrés F Cardona, MD, MSc, PhD, MBA
  • Phone Number: +573016348173
  • Email: acardona@fctic.org

Study Locations

  • Colombia
    • Bogota D.C.
      • Bogotá, Bogota D.C., Colombia, 110131
        • Recruiting
        • Fundación CTIC - Centro de Tratamiento e Investigación sobre Cáncer Luis Carlos Sarmiento Angulo
        • Contact:
        • Principal Investigator:
          • Andrés F Cardona, MD, MSc, PhD, MBA

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

Colombian adults with advanced solid tumors (gastric, colorectal, breast, cervical, head-and-neck) candidates for first-line immunotherapy, plus healthy adult volunteers. Single center: Fundación CTIC, Bogotá.

Description

Inclusion Criteria:

  • Age 18 years or older.
  • Histologically confirmed advanced (stage III unresectable or IV) gastric, colorectal, breast, cervical or head-and-neck cancer.
  • Candidate for first-line immunotherapy per current clinical guidelines.
  • Available FFPE tumor block in institutional or reference pathology archive.
  • Able to provide saliva and stool samples at V0 and follow-up.
  • ECOG performance status within protocol limits; life expectancy over 3 months.
  • Cognitive capacity to give informed consent; signed EVA-BIOBANCO and Atlas consents.

Inclusion Criteria (healthy controls)

  • No prior cancer diagnosis.
  • No active autoimmune disease; no inflammatory bowel disease.
  • No antibiotics, invasive dental treatment, immunosuppressants or corticosteroids in the prior 3 months; no severe active periodontal disease.

Exclusion Criteria:

  • Systemic antibiotics within 3 months (except short course under 5 days for uncomplicated infection).
  • Probiotics or prebiotics within 30 days.
  • Chronic proton-pump inhibitors for more than 3 continuous months.
  • Inflammatory bowel disease (Crohn, ulcerative colitis) or extensive bowel resection.
  • Pregnancy or lactation.
  • BMI under 18.5 or over 40 kg/m².
  • Uncontrolled diabetes (HbA1c at or above 9% in prior 3 months).
  • Invasive dental treatment within 3 months.
  • Patients: simultaneous randomized trial of a non-INVIMA-approved experimental immunotherapy; or no evaluable FFPE block meeting quality thresholds.
  • Inability to ensure 12-month clinical follow-up.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Patients with advanced solid tumors
120 Colombian adults with advanced (stage III unresectable or IV) gastric, colorectal, breast, cervical or head-and-neck cancer, candidates for first-line immunotherapy (standard of care). Saliva, stool and tongue scraping collected at V0, V1 (6 mo) and V2 (12 mo); archival FFPE tumor block retrieved at V0.
Drug: First-line immunotherapy (immune checkpoint inhibitors), INVIMA-approved, standard of care
Exposure observed: first-line immunotherapy with immune checkpoint inhibitors administered as standard of care (INVIMA-approved); no experimental intervention is assigned by the study. Healthy controls receive no immunotherapy.
Healthy controls
30 healthy adult volunteers without prior cancer, active autoimmune disease or inflammatory bowel disease, and without antibiotics or invasive dental treatment in the prior 3 months. Saliva and stool collected at V0 only; no longitudinal follow-up.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Oral, fecal and intratumoral microbiome signatures associated with objective tumor response (RECIST 1.1) to first-line immunotherapy
Time Frame: Baseline (V0) and through 12 months
Characterization of oral, fecal and intratumoral microbiomes and identification of taxa and diversity metrics differentiating responders (CR+PR) from non-responders (SD+PD) by RECIST 1.1.
Baseline (V0) and through 12 months
Differences in microbiome composition and diversity between cancer patients and healthy controls
Time Frame: Baseline (V0)
Comparison of alpha and beta diversity and differential taxonomic and functional abundance between cancer patients and healthy controls.
Baseline (V0)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Microbial, transcriptomic and metabolomic biomarkers associated with progression-free survival (PFS)
Time Frame: Association of microbial diversity, key taxa, MAGs and functional pathways with progression-free survival, estimated by Kaplan-Meier and adjusted Cox models.
Up to 36 months
Association of microbial diversity, key taxa, MAGs and functional pathways with progression-free survival, estimated by Kaplan-Meier and adjusted Cox models.
Microbial biomarkers associated with overall survival (OS)
Time Frame: Up to 36 months
Association of microbiome features with overall survival, estimated by Kaplan-Meier and adjusted Cox models.
Up to 36 months

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Tumor transcriptomic profile and gene-expression pathways modulated by the intratumoral microbiome
Time Frame: Baseline (V0)
RNA-Seq characterization of tumor gene-expression and identification of pathways correlated with intratumoral microbiome composition.
Baseline (V0)
Untargeted salivary and fecal metabolomic profile (subcohort, n=60)
Time Frame: Baseline through 12 months
GC-MS untargeted metabolomics of saliva and stool in a stratified subcohort (50 patients, 10 controls) to identify metabolites associated with microbiome composition and immunotherapy response.
Baseline through 12 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Centro de Tratamiento e Investigación sobre Cáncer, Luis Carlos Sarmiento Angulo

Collaborators

American Society of Clinical Oncology

Investigators

  • Principal Investigator: Andrés F Cardona, MD, MSc, PhD, MBA, Fundación CTIC - Centro de Tratamiento e Investigación sobre Cáncer Luis Carlos Sarmiento Angulo

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 11, 2026

Primary Completion (Estimated)

February 28, 2029

Study Completion (Estimated)

August 30, 2029

Study Registration Dates

First Submitted

June 24, 2026

First Submitted That Met QC Criteria

June 24, 2026

First Posted (Actual)

June 30, 2026

Study Record Updates

Last Update Posted (Actual)

July 7, 2026

Last Update Submitted That Met QC Criteria

July 3, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • ATLAS
  • CEI-232 (Other Identifier: Comité de Ética de la Investigación Riesgo de Fractura S.A)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified genomic sequences (oral, fecal and intratumoral microbiome) will be deposited in public repositories (NCBI SRA / EBI ENA) with minimal metadata (tumor type, age by decade, sex). Analysis pipelines and code will be versioned and shared via GitHub and Zenodo. Raw data and code will be made public at study close.

IPD Sharing Time Frame

Available at study close (estimated 2029); retained at least 15 years per ICH-GCP archiving policy.

IPD Sharing Access Criteria

Open access via public repositories (SRA, ENA, Zenodo) for de-identified sequence data and analysis code.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ANALYTIC_CODE

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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